Multiunit telephone-transmitter.



W. W. HANSCOM MULTIUNIT TELEPHONE TRANSMITTER.

APPLICATION FILED FEB. 21, 1917.

mfimm Patented Apr. 30, 1918.

WITNESSES: INVENTOR Ammvnvs WILLIE WALLACE HANSOOM, OF SAN FRANCISCO, CALIFORNIA, ASSIGNOR TO NATIONAL RADIO COMPANY, OF SAN FCISCO, CALIFORNIA, A CORPORA- rron' or income,

I M'O'LTIUNIT TELEPHONE-TRANSMITTER.

. Specification of Letters Patent.

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Application filed lFebruary 27, 1917. Serial No. 151,185.

larly, adapted for wireless telephony, long distance service and the like.

One of the objects of the'present invention is to provide a novel mountin for the carbon cells in the transmitter an in con-. junction therewith a common cooling chamber for the same. Another object of the invention is to provide a diaphragm prefer ably constructed of foraminated material and to provide means for freely supporting thecooling chamber and the cells to prevent distortion not only of the main diaphragm but also of the auxiliary cell diaphragm.

Further objects will hereinafter appear.

The invention consists of the parts and the construction and combination of parts as hereinafter more fully described and formed between the front, and rear claimed, having reference to the accompanying drawings, in which- Figure 1 is a central vertical longitudinal section through the telephone transmitter;

Fig.2 is a detail side elevation showing the circuit connection between two carbon cells;

Fig. 3 is a cross section partly broken away taken on the line 3-3 of Fig. 1;

F1 4 is a front view of the transmitter showing the mouth-piece removed.

Referring to the drawings in detail, A indicates the main casing of the transmitter, 2 the mouth-piece, 3 the main diaphragm, 4 the carbon cells, and 5 the cooling cylinder. The cooling chamber is in'this' instance cylindrical in shape and so shallow as to give it a disk-like appearance. It consists of anannular wall 6, a front plate 7 and a rear plate 8 which are secured together in any suitable manner. A chamber 9 is thereby lates for the reception of a cooling fluid which is circulated therethrou h in a manner hereinafter to be describe Extending through Y the front and rear plates of the cylinder 5 is a plurality of tubes 10 and extending.

is threaded for the reception .of

and 12. The inner ends of these tubes "are closed and the tube 11 is provided with a discharge opening 13 positioned in the direction indicated, while the tube 12 is provlded with an intake opening 14 facing in the opposite direction.

r A cooling medium, such as water, entering through pipe 11 will therefore discharge through the openlng 13 in the direction of the arrow shown and will therefore circulate around the tubes 10 and finally dis- Zhgrgg through the intake 14 and the Six carbon chambers are employed in the present instance and each is provided with an extension stud 15, the outer end of which a pair of lock nuts. Each stud is'inserted through a tube 10 and the nuts when applied will therefore rigidly secure the carbon chambers against the front plate 7. All metal portions of the carbon chambers are insulated from the cooling cylinder by means of thin mica tubes and washers and the electric circuit is completed through the carbon chambers in series or series multiple as may. be desired by means of thin copper strips 16 clamped under'the nuts at the back of the cooling cylinder or under the transmitter diaphragm.

The circuit passing through the carbon cells 1s first connected with the stud of the cell shown at 17. A thin copper strip 18 secured between the cell and the main diaphragm connects the cell 17 with the cell 18 or the second cell. A second strip 19 secured between the washers on the rearv side of the cylinder forms a circuit beof the cooling chamber forms a circuit be-' tween cells 21 and 24 while a fifth strip 25 forms a circuit between cells 24 and 26. Each connecting. strip is alternately positioned one on each side of the cooling cylinder' and :therebyforms a series circuit through the cells.

The front side of each carbon cell is also provided with a stud and each of said studs are secured by means of nuts and washers to the main diaphragm 3. This diaphragm by any improved means. I, however, show 1 and prefer that its outer edge be surrounded are made by means of the thin copper strips before-mentioned. The diaphragm may be of any suitable size and any suitable material and mounted in the transmitter easing by a rubber tubing or similar soft cushioning material to permit it to be clamped between the front face of the transmitter casing and the inner face of the mouth-piece which screws thereon. Thepresent diaphragm is-perforated by six circular slots such as shown at 27 leaving a small connecting bridge 28 between each perforation. The bridges are, however,,of suflicient width to form a strong connection between the inner and outer portions on the diaphragm without interferlng with the vibrations of the inner portion to any appreciable extent. The reason for perforating the diaphragm or leaving the bridges, such as shown,'is to permit of a comparatively free motion of the central portion so that it can respond readily tothe sound vibrations impinging against it and thereby have the maximum effect upon the carbon granules in the cells.

Extending through the center portion of the cooling cylinder is a tube 30 and secured to the inner face of the main casing A is a stud 31. This stud extends through the tube 30 and as the tube is slightly larger in diameter a sliding fit is permitted which prevents any binding action between the supporting stud and the cooling cylinder supporting the carbon cells. This is an important feature as it leaves the cooling cylinder free on the stud to find its own position and therefore does away with the necessity ofthe very careful adjustment necessary when the cooling chamber or back supports for the carbon cells are rigidly secured to the casing, for the reason that it is very essential to have the main and auxiliary diaphragms of the cells free to prevent distortion of the same when operating or at rest.

If both the main diaphragm and cooling cylinder are rigidly secured in place, it can readily be seen that each will have to be adjusted with reference to the other, as any tightening of the main diaphragm by screwing the mouth-piece against the rubber tubing will affect the adjustment of the diaphragm with reference to the carbon cells and the cooling chamber, this being due to the fact that the main diaphragm is surrounded by a rubber ring which is compressible and will allow the edge of the diaphragm to be moved through a certain distance by varying the pressure on the ring or gasket.

The transmitter constructed as shown may be assembled at the factory and all the working parts as a unit may be placed in the casing by unscrewing or removing the front mouth-piece. The parts when inserted are clamped and secured in position ready for service as soon as connection to the operating circuit and water supply is made and 7 there are no adjustments or tools required to make these connections. In other words, after assembly at the factory the transmitter proper is adjusted once and for all and ready to be set in the casing without further attention.

By having one large main chamber for cooling all the carbon cells instead of a separate cooling chamber for each, I simplify and cheapent-he construction, besides 8.

I wish it understood that various changes 0.

in the materials and finish and minor details of construction may be resorted to within the scope of the appended claims, and that I do not wish to limit myself to the specific design and construction here shown. 1

Having thus described my invention, what I claim and desire to secure by Letters Patent is 1. In a multi-unit telephone transmitter a casing, a dia hragm, a cooling cylinder mounted within the casing, a plurality of carbon cells secured on one side of the cooling cylinder and on the opposite side to the diaphragm, and means for circulating a cooling medium through the cylinder.

2. In a multi-nnit telephone transmitter, a casing, a diaphragm, a cooling cylinder slidably mounted within the casing, a plurality of arbon cells secured on one side of the coolin cylinder and on the opposite side to the diaphragm, and means for circulating a cooling medium through the cylinder.

3. A telephone transmitter comprising in combination a casing, a diaphragm, a serlcs 1:

which said terminal ends are secured, and 1? means for circulating a coolin liquid around sa1d terminal ends and through the cylinder. 4. A telephone transmitter comprising in combination a casing, a diaphragm, a series of resistance cells each of which is rigidly 1 macaw? connected at one end to the diaphragm and has a terminal projecting outwardly from its opposite end, a common cooling cylinder in which said terminal ends are secured, a stud secured in the casingin which said cylinder is slidably mounted and means for circulating a cooling liquid around said terminal ends and through the cylinder.

5. In combination with the diaphragm of a telephone transmitter of a series of resistance cells secured to the diaphragm, aterminal projection on each cell, amcomuxnon cooling cylinder through which said terminal members pass and towhich they are rigidly secured, and means for insulating the cells and terminal members with relation to the/cooling cylinder and diaphragm.

6. In combination with the diaphragm of a telephone transmitter of a series of resistance cells secured to the diaphragm, a terminal rojection on each cell, a common cooling cy inder through which said terminal members pass and to which they are rigidly secured, means for insulating the cells and terminal members with relation to the cooling cylinder and diaphragm, and a supporting member upon which the cylinder is slidably mounted,

In testimony whereof have hereunto set my hand in the presence of two subscribing 30 witnesses.

WILLIAM WALLACE HANSG 0M.

Witnesses:

JOHN H. Hnnnme, W. W. Hauler. 

